Chester A Farris

US Patent:

55146180, May 7, 1996

Filed:

Feb 23, 1995

Appl. No.:

8/395494

Inventors:

Robert O. Hunter - Rancho Santa Fe CA
Chester A. Farris - Yorba Linda CA

Assignee:

Litel Instruments - San Diego CA

International Classification:

H01L 21786

US Classification:

437 60

Abstract:

A direct laser ablation process is disclosed for forming thin film transistors on liquid crystal matrix for enabling typically color presentation from a flat panel display. The thin film transistor is of the type having an active matrix addressing scheme wherein a capacitor when charged turns on and maintains in the "on" state a field effect transistor to permit passage of light through a liquid crystal display. All patterning of the display is done either by utilizing deposition, direct ablation of an etch block followed by etching, or more preferably deposition followed by direct laser ablation. In the preferred embodiment, aluminum channels are made by deposition followed by a direct laser ablation. Anodizing follows with deposition of a silicon-nitrogen layer. With respect to the capacitor, indium tin oxide is deposited to complete a matrix capable of selectively strobing and charging the capacitor for each matrix element.